The Neurochemistry Core will integrate and consolidate the activities performed in several basic laboratories of this Center into three units, under the direction of Drs Moore, Cooper and Javitch, respectively: 1) In vivo and ex vivo determination of brain catecholamine, indoleamine and amino acid transmitter levels (Moore). This unit will provide logistical support and technical expertise to projects of the Center that employ in vivo microdialysis in rodents and primates (Projects by Laurelle, Kandel, Rayport) including experimental design, implementation, and chromatographic analysis of catecholamines, indolamines and amino acids in in vivo brain dialysate samples and ex vivo brain tissue homogenates (Projects by Laurelle, Javitt, Kandel, Rayport). 2) Pharmacokinetic Unit (Cooper). This unit will develop and perform analysis of plasma levels of pharmacological agents (e.g. MK 801, NNC 112, SCH 39166, amphetamine, PCP, risperidone) used in mice (Projects by Kandel, Rayport ); non-human primates (Projects by Laurelle and Project by Javitt) and humans (Projects by Abi-Dargham and Laurelle). 3) Receptor Binding Unit (Javitch). This unit will integrate activiiies performed in the laboratories of Javitch, Rayport, and Huang. The first mission is to perform in vitro binding assay and to characterize candidate radioligands developed by the Brain Imaging Core and Projects by Abi-Dargham and Project by Laurelle. The second mission is to study the impact of receptor trafficking on binding affinities of D2 and D1 radiotracers. The latter investigation will provide important information for imaging studies using endogenous competition techniques such as used in Project by Laurelle, and will contribute to the development of novel radioligands with binding that is sensitive to changes in synaptic/extracellular concentrations of endogenous transmitters, specifically dopamine and glutamate (see Brain Imaging Core). In summary, the Neurochemistry Core will share personnel and will work closely with Projects by Abi-Dargham, Laurelle, Javitt, Kandel & Rayport and the Brain Imaging Core and Cellular/Molecular Core to provide screening and hypothesis-directed characterization of neurotransmitter profiles in animal models, development of novel methods for combining in vivo microdialysis and functional brain imaging in primates and rodents, and development of methods for characterization of candidate radioligands for functional brain imaging.